In the field of imprinting design onto articles of manufacturer using dye-sublimation, images are transferred from a carrier medium using heat and pressure to activate the printed dyes, causing them to turn gaseous through sublimation from their solid state and to subsequently diffuse into a softened polymer matrix under the influence of heat and pressure. For example, an early patent disclosing a dye sublimation transfer was presented in U.S. Pat. No. 4,021,591 issued to Devries. Another sublimation example is shown in a method of imaging a ceramic mug as disclosed in U.S. Pat. No. 4,943,684 issued to Kramer.
Certain fibrous materials such as polyester fabric and certain synthetic organic polymers such as acetyl, polycarbonate, and nylon can accept the diffusion of sublimable or disperse dyes directly and have no need to be coated before receiving the image. However, their natural ability to accept the diffusion of the dye does not ensure long term persistence of these dyes and often the image will blur or fade over time.
For this reason, and to render articles suitable for dye sublimation decoration on persistent, long-term hosts, synthetic organic coatings are typically formulated and employed to pre-coat the substrate being decorated prior to the transfer of the image. An example patent disclosing such coatings used prior to the sublimation of images onto ceramic tiles is U.S. Pat. No. 4,174,250 issued to Durand.
One article that uses a transferred image by a process of dye-sublimation is acrylic blocks. The thickness of these acrylic blocks is typically around 1″ in order to position the block in a stable fashion without an additional base and for easy viewing of any decorations that might be applied to the block, such as photographs. Due to the ease at which larger panels can be knocked over, these blocks have been available in dimensions of up to 8″×10″. Panels with a thickness of greater than 1″ are not generally decorated due to high cost.
One advantage of acrylic blocks is that its flat, polished edge forms a reflective plane within the block and causes an appealing optical effect. Another advantage is that the acrylic can be fabricated from “sheet-stock” on a just-in-time inventory basis where the larger coated sheet can be cut down as needed into various sizes immediately prior to shipping a decorated product.
However, a disadvantage of acrylic articles is that a one inch thick acrylic is not only expensive but heavy, and the stability of a 1 inch base limits the potential height of an acrylic article. Thinner acrylic panels can be offered as a solution, however they require a stand to support them and the thinner they are more the susceptible to warping during manufacturing. Adding weights to maintain a flat shape during manufacturing can be used, but such weights can lead to surface damage of the acrylic.
In response, another article that has become popular in recent years for decorating—curved glass media. Curved glass is transparent and has a coating applied onto the outer side of the curve allowing an image to be viewed through the glass. Also, current techniques and formulations allow for images to be viewed from both sides. Hence, glass media have become popular for gifts and photo displays, and often are decorated for such uses.
The advantage of utilizing glass is that the glass can be curved eliminating the need for a base, and glass does not require a significant thickness with thicknesses of 0.1875″ typical. Moreover, glass can be formed into a curved shape and can therefore act as its own support on a flat surface, thereby not requiring an independent stand like a thin acrylic article might require. Other advantages include the ability for coated curved glass to be heated without warping.
However, some disadvantages to curved glass exist, namely a relatively high weight, the potential for easy breakage, and safety concerns in a home environment, especially when young children are present. Maintaining a just-in-time inventory is also challenging for manufactures due to uncertain shipping times from international suppliers of glass blanks. Custom decorators must therefore invest in sizable inventories of each size if they are to be able to respond to rapid surges in demand, such as during holiday seasons or during popular photo demands, which further exposes the manufacture to risk if excess product inventory remains unsold.
Hence, both glass and acrylic articles each have their own advantages and disadvantages. However, curved glass has an additional factor which limits its acceptance in the marketplace. Curved glass experiences a much longer time to transfer a dye-sublimation image onto the glass article. The transfer of an image by dye-sublimation typically requires 7-12 minutes per image depending upon the process employed the thickness of glass, and coating composition. Acrylic does not suffer from this limitation. Therefore, it would be desirable to use acrylic as a gift article if the acrylic could be curved like glass, but also be susceptible to the application of a dye-sublimation image in the curved shape in a relatively rapid manufacturing process.